1. Field of the Invention
The present invention relates to a format structure of serial data and a serial data conversion apparatus, and more particularly, to a format structure of serial data including video/audio/and control packet signals transmitted from a source device as an optical signal form through one optical cable, and an apparatus for converting the video/audio/and packet signals into serial data so that they may have the format structure.
2. Description of the Related Art
With a development of electronics technology, many flat panel display devices have been developed. Also, as a display device such as a television receiver and a monitor for displaying videos, a thin and light flat panel display device is being adopted instead of a voluminous and heavy CRT.
The flat panel display device is divided into a device using an inorganic substance and a device using an organic substance. The device using an inorganic substance includes a plasma display panel (PDP) using photo luminescence (PL), a field emission display (FED) device using a cathode luminescence (CL), and etc., and the device using an organic substance includes a liquid crystal display element (LCD), an organic electro-luminescence (EL) display device, and etc.
Among these flat panel display devices, the PDP has a high brightness, a high luminescence efficiency, a wide viewing angle, excellent heatproof, coldproof, and quakeproof characteristics, a light weight, and a cheap fabrication cost. Also, the PDP can easily realize full colors, thereby widely being adopted as a display screen of display devices such as a television receiver and a monitor. Besides, a display device using the PDP as a display screen is light and thin, thereby being much developed as a wall-mounted type.
In order to make the display device output videos and audios, video and audio signals outputted from a source device such as a set top box are inputted into the display device using the PDP. Like this, in the conventional art, plural cables were connected between the display device and the source device in order to output videos and audios of the display device. According to this, the video and audio signals of the source device were transmitted to the display device through the cables, and certain control signals were transmitted between the display device and the source device through the cables.
Hereinafter, transmissions and receptions of the video, audio, and control signals between the display device and the source device through the cables will be explained.
FIG. 1 is an exemplary view showing a connection relation between a display device and a source device in accordance with the conventional art. Herein, the reference numeral 100 denotes a wall-mounted type display device using the PDP as a display screen such as a wall-mounted type monitor or a wall-mounted type television receiver.
The reference numeral 110 denotes a digital device such as a digital video tape recorder (VTR) or a digital video disc (DVD) for outputting a transport packet stream corresponding to digital video and audio signals by reproducing certain media, and the reference numeral 120 denotes an analogue device such as a VTR or a computer system for outputting analogue video and audio signals by reproducing media such as a video tape.
The reference numeral 130 denotes a source device such as a set top box for receiving a digital broadcasting signal, receiving the transport packet stream outputted from the digital device 110 and analogue video and audio signals outputted from the analogue device 120 and thus selectively switching them, and transmitting the switched signals to the display device 100.
In the conventional device, the plural digital devices 110 and the source device 130 are connected by wire such as an IEEE 1394, and the digital devices 110 output a transport packet stream corresponding to digital video and audio signals by reproducing certain media. The outputted transport packet stream is transmitted to the source device 130 through the IEEE 1394 cable and etc.
The analogue devices 120 and the source device 130 are connected by a coaxial cable. The analogue devices 120 generate analogue video/R,G,B/audio signals by reproducing certain media, and the generated analogue signals are transmitted to the source device 130 through the coaxial cable and etc.
The source device 130 receives a digital broadcasting signal by a mounted advanced television systems committee (ATSC) tuner and etc., and converts a transport packet stream corresponding to the received digital broadcasting signal and a transport packet stream inputted from the digital devices 110 into analogue video and audio signals. Then, the source device 130 switches the converted analogue video and audio signals and analogue video and audio signals inputted from the analogue devices 120 by a user's selection, and transmits to the display device 130. Herein, the source device 130 transmits the analogue R, G, B signals and analogue audio signals of L/R channels to the display device 100 through respective cables.
Also, additional control and response cables are connected between the display device 100 and the source device 130, and through the control/response cables, certain control signals and response signals corresponding to the control signals are transmitted.
However, in the conventional art, the display device 100 and the source device 130 are connected by plural cables. Therefore, in case that the display device 100 is installed on a wall as a wall-mounted type and the source device 130 is installed on a shelf, cables for transmitting the analogue R, G, B signals and the analogue audio signals and cables for transmitting the control signals and the corresponding response signals are exposed onto the wall between the display device 100 and the source device 130. Besides, the exposed cables have thick diameters thus to have a bad appearance.
Accordingly, the display device 100 and the source device 130 can be connected to each other by one optical cable which is thin thus to be hardly noticed from a far distance, and the source device 130 can convert video/audio/control signals and video/audio signal characteristics into an optical signal thus to transmit to the display device through an optical fiber. Then, the display device 100 can receive the optical signal and process it.
In order to transmit the respective signals from the source device 130 to the display device 100 through the optical fiber as the optical signal form, 8-bit data has to be converted into 10-bit data so as to be preferably transmitted as the optical signal form, and the optical signal has to be transmitted by being converted into serial data of a certain format since it can not be transmitted as parallel data.
Therefore, the source device 130 selects the respective signals by an order of the certain format thus to encode, and converts parallel data of 8 bits into data of 10 bits. Then, the source device 130 converts the parallel data of 10 bits into serial data again, and transmits as the optical signal form through the optical fiber.
However, in case that the video/audio/control signals are converted into the serial data by the source device 130 and transmitted as the optical signal, clock signals according to the video/audio signals, horizontal/vertical synchronization signals according to the video signals, horizontal/vertical active signals according to the video signals can not be transmitted as the optical signal form due to characteristics of the optical cable. Therefore, in case that video/audio/control signals are transmitted by being converted into serial data, the display device 100 has to be able to restore the clock signals, the horizontal/vertical synchronization signals according to the video signals, and the horizontal/vertical active signals according to the video signals into serial data.